Surgical operations commonly employ power tools to perform surgical functions, such as cutting and drilling. Such tools are commonly known as surgical handpieces. The surgical handpieces are held and controlled by the surgeon to aid in surgical techniques.
Surgical handpieces require a power source to operate, usually requiring a particular voltage and a particular current from an electrical power source. Different surgical handpieces have differing voltage and current requirements. Multiple surgical handpieces of different kinds, types and brands are typically available in operating room. It becomes impractical for the operating room to have every kind, type and brand of power supply or control on hand to meet the needs of the multiple kinds, types and brands of surgical handpieces.
Therefore, a single piece of equipment, known as a controller, has been used in operating rooms to control multiple kinds, types and brands of surgical handpieces. Multiple surgical handpieces, typically different surgical handpieces at different times, can all connect to a single controller. The controller can be set or programmed to provide the proper kinds and amounts of electrical power and control signals for each surgical handpiece. This can greatly simplify an operating room.
Some surgeons prefer to use a foot piece, such as a pedal, to control a surgical handpiece. Other surgeons prefer to use a handswitch mounted on the surgical handpiece itself to control a surgical handpiece. Of course, the same surgeon may have a different preference depending upon the particular surgery involved and/or the particular surgical handpiece involved.
Since different types of control, e.g., hand or foot, are available, a controller must know which control the surgeon will use.
A handswitch typically can be removably mounted on a surgical handpiece for hand control. Or the handswitch can be removed from the surgical handpiece for foot control, e.g., by pedal. The controller must know which type of control is being used.
Of course, a switch or program setting on the controller could perform this task. However, an automated system of determining the method of control could simplify the process and eliminate the potential for error by setting a switch to an incorrect position or making an incorrect program setting.
Prior art devices have used magnetic elements, such as a Hall Effect sensor, to sense whether or not a handswitch is attached to a surgical handpiece. Typically, a Hall Effect sensor is located in the surgical handpiece and a magnet is located in the handswitch. The Hall Effect sensor detects the presence of a magnetic field generated by the magnet in the handswitch and signals the controller that a handswitch is present and hand control will be performed.
However, such magnetic sensors are prone to error. The simple presence of a magnetic field in the proximity of the surgical handpiece in the operating room could fool the magnetic sensor into thinking a handswitch was present when it was not present. Of course, there are many pieces of electrical equipment, typically all generating magnetic fields, present in a typical operating room. This could result in erroneous operation of the surgical handpiece. This could result in the surgical handpiece starting or stopping, for example, with potentially disastrous results.
Hall Effect sensors are also prone to degradation over time potentially leading to erratic operation over a period of time. Hence, magnetic sensing of the presence of handswitches on surgical handpieces is prone to error.
Thus, there is a need for equipment to reliably detect the presence of a handswitch on a surgical handpiece.